1. Field of the Invention
The invention relates to a closure for a container, said closure ensuring supply and removal of media. A closure of this type is used in particular for single-use reactors, mixing reactors and bioreactors in pharmaceutics and biotechnology.
2. Description of the Related Art
The closure of a container is known in many different embodiments. For containers in the sphere of laboratory technology and in industrial use, such as in the pharmaceutical production of products or in foodstuff technology, closures are required which can be handled simply and reliably. A particularly cost-effective production is required in particular in the sphere of single-use products.
U.S. Pat. No. 5,975,369 discloses a drinking bottle closure, in which a first sleeve which is connected to the drinking bottle has a cylindrical ram. The closure furthermore has a second cylindrical sleeve having a smaller diameter than the diameter of the first sleeve connected to the bottle, wherein the cylindrical sleeve having the smaller diameter has, at its upper end, an opening which, in the closed state of the bottle, is closed by the cylindrical ram. The cylindrical sleeve having the smaller diameter can be displaced axially along the ram. By means of locking devices on the ram and the sleeve having the smaller diameter (for example by means of stops on the inner wall of the sleeve having the smaller diameter), the sleeve having the smaller diameter is prevented from being pulled off from the ram. In this case, it has proven disadvantageous that there is a dead space in the closure itself. There are structurally induced clearances between the cylindrical sleeves and on the ram. Correct use for, for example, drinking bottles permits the medium to flow back into the container, since an attachment to the container cover is provided. When attached to the bottom of a container, a closure of this type would create space for a medium which remains in said clearance. A closure of this type is unfavorable for use on a single-use reactor, mixing or bioreactor, since the portion of medium remaining in the dead space of the closure is not subjected to the same conditions as the medium in the container. It is also possible for particles to be deposited in the dead space and to block the latter up.
US 2003/0121879 A1, U.S. Pat. Nos. 6,758,359 B2, 6,321,924 B1 and WO 2005/044685 A1 disclose bottle closures for beverage and cleaning agent containers, said bottle closure constituting further developments of the closure disclosed in U.S. Pat. No. 5,975,369 in respect of the configuration of the sleeves, the ram and a protective cap covering said components. Even the further developments do not solve the problem of the dead space, since the correct use is entirely different.
Finally, US 2007/0102450 A1 discloses a closure for a container, which has a closure part, a flange and two sealing rings, wherein the closure part is a hollow piston which is closed at one end and is open at the other end, and wherein there are bores below the closed side, through which the medium flows when the closure is open. Seals are located above and below the bores. In the closed state, the closed side together with the upper sealing ring closes the flange opening.
In a first embodiment disclosed in US 2007/0102450 A1, the hollow piston can be displaced into the container for the opening. A disadvantage in this case is that a part which projects into the container interferes with elements which can be provided on the inside of the container, such as, for example, stirrers or gas-injecting devices, which are preferably, like a closure, provided centrally.
In a second embodiment, the hollow piston can be pulled back out of the container into a “preliminary space”. In the open state of the closure, the medium passes into the preliminary space and from there through the bores into the hollow piston. A disadvantage here is the absence, caused by the construction, of locking, and therefore there is no security against unintentionally completely pulling out the hollow piston. A further disadvantage is the unfavorable deflection of the container contents during the outlet operation. The medium is repeatedly deflected via the closed end and by means of the bores which are located in the preliminary space in the open state, and therefore experiences a relatively high degree of flow resistance. This firstly has a negative effect on substances which are sensitive to shearing and secondly the volumetric flow is therefore reduced, which leads to the container taking longer to empty. The preliminary space has furthermore proven disadvantageous when the closure is in a closed state. In the event of a leakage at the sealing ring attached to the container interior, but also in the case of inadequate or defective closing, the preliminary space would fill with the medium. In the case of small leakages, the preliminary space fills first of all and the medium passes only after some time through the bores into the hollow piston and from there into the outlet tube. Furthermore, the preliminary space results in a dead space which is not desirable with regard to a hygienic design. Possible cleaning therefore becomes problematic, and, for example, bacteria could multiply or cells could die. It is also possible for substances remaining behind to develop differently and, during removal of the medium which, by the closure being opened, inevitably comes into contact with substances remaining back in the preliminary space, corresponding analyses are falsified.
A joint disadvantage of both embodiments of US 2007/0102450 A1 is that, in the event of a leakage at both seals or, in the open state, if there is a leakage at the seal below the bores, the container contents emerge into the open. This may lead to a hazardous contamination of staff and/or the environment and furthermore jeopardizes a sterile state which is to be maintained.
The invention is therefore based on the object of providing a closure for a container, which closure does not have any dead space, and has favorable guiding of the media and a high degree of security.